Is a substance and a mixture the same thing?
a mixture is a combination of two or more pure sub.
In a homogenous mixture the substance are so evenly distributed that it is difficult to distinguish one substance in the mixture from another but it only contains only one substance and it will appear the same. In a heterogenous mixture the parts of the mixture are noticeably different from one another and the mixture is different and kind.
A substance can any material, solution, or mixture, such as water, salt, glue, or gunpowder. A pure substance is one that contains the same element or compound throughout. Salt is a pure substance, but when added to water, it becomes a mixture. Gunpowder is basically a mixture of three pure substances (compounds).
The FREEZING POINT ----- which for a pure substance (as opposed to a mixture)is the same thing as the melting point since they are both the point at which the liquid phase of a substance would be in equilibrium with the solid. For a mixture, the two would be different and you would get a freezing point range that started at the freezing point and ended at the melting point
A pure substance is a substance that has only that substance in it. One kind of molecule or atom. A homogenous mixture can have different molecules and/or atoms in it, but they have to be in the same physical state. Water mixed with honey would be a homogenous mixture, because they are both liquids. Water mixed with sand would be heterogeneous.
Mole percent, or molar percent of a substance is the ratio of the moles of a substance in a mixture to the moles of the mixture. It represents the number of moles of a substance in a mixture as a percentage of the the total number of moles in the mixture. Mole % = (mol substance in a mixture) / (mol mixture) * 100